This decision is acceptable to me.
- Bob
At 01:53 PM 7/15/2003 -0400, Jim Hendler wrote:
>Dear Bob-
> Thank you for your comment, the working group has considered it
> carefully. With respect to qualified keys, we considered how this could
> be added to OWL - see the discussion thread starting at [1] and
> particularly [2]. The group considered the addition of Qualified
> Cardinality Restrictions, which we believe are needed to implement the
> sort of global keys you need. However, the WG decided to postpone the
> issue of QCRs as discussed in my response to Alan Rector at [3].
> We also considered the issue of Compound Keys. We decided this was an
> important enough area to open an issue on our issues list explicitly. We
> did not, however, come up with a solution as to how to address
> these. Instead we also decided to postpone this issue. The issue text is:
>
>>TITLE: Compound Keys
>>DESCRIPTION:
>> Relational Databases often use keys that are composed of multiple
>> fields. OWL allows keys using owl:InverseFunctionalProperty for a
>> single field (property). It would be desirable for OWL to provide the
>> compound keys capability as well.
>>STATUS: POSTPONED
>>RAISED BY: J. Hendler based on a Last Call comment raised by Bob
>>MacGregor:
>>http://lists.w3.org/Archives/Public/public-webont-comments/2003May/0019.html
>>
>>Closing Comments:
>>
>>While compounds keys would be desirable to add, there is some difficulty
>>in adding them in the current OWL syntax, similar to the problem arising
>>for "qualified" properties (see discussion under issue 3.2). In
>>addition, for the OWL DL profile, it is still something of a research
>>issue (c.f.
>>http://www.dis.uniroma1.it/~calvanes/papers-html/DL-2000.html) as to how
>>these are best realized by DL reasoners. There is also a question as to
>>whether mixing datatype and object type in a compound key would be
>>allowed, and whether it would cause difficulties to reasoners.
>
>
>Please let us know if this decision to (a) acknowledge that our
>design is lacking, but (b) postpone further design work to a future
>version is acceptable.
> -Jim Hendler
>
>
>[1]
>http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0064.html
>[2] http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0085.html
>[3]
>http://lists.w3.org/Archives/Public/public-webont-comments/2003Jun/0024.html
>
>
>--
>Professor James Hendler hendler@cs.umd.edu
>Director, Semantic Web and Agent Technologies 301-405-2696
>Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax)
>Univ of Maryland, College Park, MD 20742 *** 240-277-3388 (Cell)
>http://www.cs.umd.edu/users/hendler *** NOTE CHANGED CELL NUMBER ***
=====================================
Robert MacGregor
Senior Project Leader
macgregor@isi.edu
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Mobile: 310/251-8488
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